<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>第三题</title>
</head>

<body>
    <script>
        function Exchange(x, y) {
            let temp
            temp = x
            x = y
            y = temp
            console.log(`x为：${x}`)
            console.log(`y为：${y}`)
            return x, y
        }
        let x = +prompt('请输入x')
        let y = +prompt('请输入y')
        Exchange(x, y)
    </script>
</body>

</html>